1-First Step: Prepare the Ingredients Cook the 1 lb. ground beef with the 1 cup diced white onion, 1/2 tsp. salt, 1/4 tsp. pepper, 1/4 tsp. garlic powder, and 1/2 tsp. dried leaf oregano in a skillet over medium-high heat; keep 2-3 tablespoons of liquid in the meat mixture for moisture. Once browned, set it aside. This step ensures your meat is flavorful and ready for layering, adding that essential savory base to your dish.

2-Second and Third Steps: Layering in the Slow Cooker Spray the slow cooker with non-stick spray to prevent sticking. Pour half of the 24 oz. marinara sauce into the bottom, then add half of the 25 oz. frozen ravioli in a single or slightly overlapping layer. Spread the browned ground beef mixture on top, followed by the remaining ravioli and the rest of the marinara sauce.

3-Final Steps: Cooking and Serving Sprinkle the 8 oz. shredded mozzarella cheese evenly on top, cover, and cook on low for 4 hours. Once done, let it rest a bit before serving to make slicing easier. For adaptations, swap ingredients as you go to fit dietary preferences, like using vegan cheese or different proteins.

4-Here are some quick assembly tips in a list to keep things organized: * Gather all items before starting to save time. * Use even layers for the best results. * Adjust cooking time if using refrigerated ravioli.